The present invention relates to an apparatus for use in audio monitoring of carbon dioxide. The present invention can be used in administering anesthesia as well as in any situation where carbon dioxide is being monitored. One of the uses for the present invention in anesthesia will be in the process of blind nasal intubation. This process is often elected for use in intraoral operations when anatomic abnormalities or disease of the upper airway make direct laryngoscopy difficult, or in order to facilitate long term intubation of the lungs.